National introduced their brand new DC-10s to the public by holding an "Air Fair" at Miami International Airport on a Saturday in late November 1971. As I recall they ran a full-page ad in The Miami Herald promoting the event. They sold tickets to the public for $10 and everyone stood in line down the length of Concourse 3 (now F) waiting their turn to go on a 30 minute ride around South Florida, including up the length of Miami Beach at low level. We stood in line for what seemed to be a long time and as we neared the front we heard that a flight attendant had accidentally popped the escape chute from one of the main cabin doors. Fortunately National brought another new DC-10 over from the hangar and the line started moving again.